Spark plug problem

[vetteater13]

Have a 99 seadoo speedster sk. Over the weekend the starboard engine cut out and died, checked the plugs and the back plug was loose, tighted it back up and the motor fired right back up and ran fine. My problem is felt like the plug might be stripped and not too sure what or how to fix without getting a new head and gasket. Would also like to know why this happened, because i always torque plugs to spec. any suggestions or help would be greatly appreciated

 

[rookie101]

The threads can just wear out over time. Think about how many times the plugs have been in and out of the head. Aluminum threads don't always last, all it takes is a bit of carbon build up or dirt on the end of the plug when you turn it out to start the problem.

The good news is Heli Coil makes repair kits just for spark plug holes. Take the head off (you will need a new gasket) and match up the depth of the threads to a new insert. The insert should only be a couple of bucks, but you may have to rent the insert tool from some place like Autozone. Install the insert on the work bench to keep the metal filings out of the engine (this is why you need to pull the head), then reinstall the head.

Aaron:cheers:

 

[vetteater13]

Rookie101, the motor had a complete overhaul as of 8-9-08, maybe 20 hours on it. I have been running 93 octane gas, for thats all thats available. spark plug is a ngk br 8es as manual requires. i did pull the plug and it looked a little black but ive seen worse. there was no little build up balls. Fore surely it didn't get to hot and scortch the piston and melt the threads, they look fine.